Field of Invention
The present invention relates generally to the stoppering of receptacles which have a neck, and in particular to a stoppering device intended for the restoppering of bottles containing gaseous beverages such as champagne.
A stoppering device constituting prior art for the present invention is described in U.S. Pat. No. 3,779,412. However, the present invention is more specifically related to applicant's prior French Pat. No. 2,476,608. The device described in this French patent incorporates a cylindrical inner part whose lower slotted section takes the form of a multilobe skirt. Each lobe has, at its extremity, an inner tooth adapted to engage the neck of the bottle below the rim surrounding the mouth and to apply a sealing member onto the mouth.
This prior device further comprises a cylindrical outer part constituting a locking member adapted to surround the skirt of the inner part and to slide along it in order to engage the teeth below the rim and maintain them at that position. The movement of the outer part with respect to the inner part is a helicoidal movement from an upper to a lower position known as the locking position. This movement is guided by means of a pair of ramps formed by recesses on the outer face of the inner part, and a pair of tenons which protrude from the inner face of the outer part.
Each tenon is adapted to travel on its corresponding ramp between a locking position and an unlocking position, each of these positions representing a stable position of the tenon on its ramp. It is to be understood that the expressions "top" and "bottom" are used with respect to the vertical position normally assumed by a receptacle.
In one of the embodiments of the device described in the above-identified French patent, the ramps have an asymmetrical U or V shape, the shorter arm of which defines the locking position, while the longer or higher arm defines the unlocking position of the lobes of the skirt. The width of the ramp is substantially constant and equal to the diameter of the tenons which are of circular shape.
In practice, it has been found that such prior art stoppering devices sometimes suffer from the drawback that they cannot be removed after having been placed in position on a bottle neck. This drawback appears to be due to the fact that in order to pass from one arm of the ramp to the other and, in particular, from the bottom arm to the top arm or from the closed position to the open position, it is necessary to cause the tenons to pass through a transition portion of the ramp along which rotary movement of the outer part with respect to the inner part is permitted only in the event that the inner part is more firmly connected to the neck than the outer part is to the inner part. This is true when the mouth of the neck is dry, but it is no longer true when the mouth of the neck is wetted by the liquid contained within the bottle. The same drawback can, of course, be experienced when restoppering while the neck is wet. As a consequence, it is not possible to lock the stopper on the neck.